Headphones allow listeners to listen to music, voices, or other audio content without disturbing others nearby. However, listeners sometimes wish to share their music or other audio content with others, but conventional headphones don't reproduce sounds at high enough volume levels for this purpose. Therefore, until recently, listeners had to use headphones for personal listening and separate loud speakers for group listening.
Headphones with larger, more powerful speakers and means for broadcasting sounds therefrom have been developed to eliminate the need for separate loud speakers in some applications. However, these headphones also suffer from several disadvantages that limit their utility.